Displacement of Dental Implants Into the Maxillary Sinus: A Retrospective Study of Twenty-One Patients Nicola Sgaramella, MD, DDS; Gianpaolo Tartaro, MD, MDS, PhD; Salvatore D’Amato, MD, MDS, PhD; Mario Santagata, MD, MDS, PhD; Giuseppe Colella, MD, MDS, PhD
ABSTRACT Background: One possible complication of implant surgery in the posterior maxilla is the displacement of implants into the maxillary sinus. Purpose: To report on clinical and radiological findings and on biological, surgical, and biomechanical considerations in cases of implant displacement. Materials and Methods: This is a retrospective study of 21 patients referred to the Department of Head and Neck Surgery, Second University of Naples, due to implants displaced into the maxillary sinus. Patient, implant, and treatment data were collected, and 1-year follow-up was made. Results: A total of 24 displaced implants were diagnosed and surgically removed through an antrostomy in the lateral sinus wall. Implant displacement occurred after functional loading in only one case; in the remaining cases, displacement occurred either perioperatively or postoperatively prior to loading. Besides the displacement, eight patients suffered from maxillary sinusitis, treated with a Caldwell-Luc operation. Healing was uneventful for all patients, and no sinusitis relapse or late postoperative complication was present at 1-year follow-up. Conclusions: It is reasonable to affirm that the major cause of displacement of implants is related, most of the time, to incorrect treatment planning and/or a poorly performed surgical procedure. When implant displacement occurs, the displaced foreign body has to be removed in order to avoid sinus pathology. KEY WORDS: dental implants, displacement, maxillary sinus, osseointegration, primary stability, sinus elevation
dental implants.3–15 There are also reports of oral implants displaced in the sphenoid16 and in the ethmoid sinus.17 Titanium dental implants have been used worldwide for over 40 years. The failure rate of endosseous implants is relatively low, but it is generally greater in the maxilla than in the mandible. Several anatomical features of the maxilla may prompt a higher rate of implant failure than that recorded in the mandible. The upper jaw often shows type IV alveolar bone (poor-quality, low-density cancellous bone and a very thin cortical layer). Besides, the dorsal segment of the maxilla presents some unique anatomic features and limitations. As is well known, tooth loss implies that the necessary stimulus to maintain bone trophism has disappeared, resulting in resorption of the alveolar process, which, in the posterior maxillary region, means a close relation between the sinus floor and the alveolar crest. Furthermore, pneumatization of the sinus through centrifugal
INTRODUCTION A foreign body in the maxillary sinus is a rare finding. Possible causes are injury or accident and dental treatments. The most commonly found foreign bodies are displaced fractured dental roots or, in some instances, whole teeth following tooth extraction procedures.1,2 Other foreign bodies include dental burs, endodontic material, impression materials, and, more recently,
Department of Oral and Maxillofacial Surgery, Second University of Naples, Naples, Italy Corresponding Author: Dr. Nicola Sgaramella, Department of Oral and Maxillofacial Surgery, Second University of Naples, Piazza Miraglia, 80100, Naples, Italy; e-mail: [email protected] © 2014 Wiley Periodicals, Inc. DOI 10.1111/cid.12244
1
2
Clinical Implant Dentistry and Related Research, Volume *, Number *, 2014
bone resorption, induced by the osteoclastic activity of the periosteum underlying the schneiderian membrane, usually occurs in the edentulous posterior region. These unique anatomical and physiological features, together with the progressive widening of implant treatment indications, make implant rehabilitation of the posterior maxilla a challenging issue; complications such as implant displacement into the maxillary sinus, apparently rare and sporadic, may well be underestimated. Indeed, the incidence of implant displacement into the maxillary sinus remains unknown because of the lack of cohort studies and the relatively few published case reports.3–15 The following paper is a retrospective study of 21 patients referred to the Department of Head and Neck Surgery, Second University of Naples, for implants displaced into the maxillary sinus. The surgical treatments performed shortly after the diagnosis of this complication, including treatment for possibly associated sinusitis and/or oroantral fistula, and the 1-year follow-up results are reported. MATERIALS AND METHODS In a 20-year period between 1990 and 2010, 21 patients (10 male, 11 female), aged 35–70 (mean 55 years), were referred to the Department of Head and Neck Surgery, Second University of Naples, due to clinical and radiological signs of implants displaced into the maxillary sinus (Figure 1). The displacement occurred during or after implant insertion in the posterior upper jaw. None of the patients underwent implant surgery in postextractive sites. Eight of these patients sought medical care because of sinusitis symptoms, one of the patients suffering also from the presence of an
oroantral fistula, while the remaining 13 patients were asymptomatic, so the detection of the displacement was done during other dental treatments or routine controls. The following patient data were collected: age; gender; smoking habits; type of edentulism; number of displaced implants; implant sites; implant type (conical, cylindrical or Tramonti); implant diameter and length; other displaced components; year of implant insertion; intervening time between implant insertion and detection of implant displacement; previous functional loading of the displaced implant; bone height at the implant site, which was estimated from conventional x-rays (panoramic and intraoral radiographs) taken at implant insertion time or at implant displacement diagnosis time and from the computed tomography (CT) or cone beam computed tomography (CBCT) examination performed prior to surgical treatment of the complication (the only exception being the case of patient 16, for whom a CBCT exam performed prior to implant surgery was available); sinus lift procedure simultaneous with implant placement; signs and/or symptoms of sinusitis; surgical treatment performed; and postoperative complications and/or relapse of sinus pathology at 1-year follow-up (Table 1). RESULTS A total of 24 displaced implants were diagnosed and surgically removed. Most of the implant displacements occurred during the second decade of the period covered by the present study. Among the patients with displaced implants, the majority were smokers (71.4%), and 15 out of 21 patients were partially dentate in the maxilla.
Figure 1 Patient 21, CT examination prior to the surgical removal of the displaced implant.
Male
Male
Female Female
Female
Male
Male
Female
Female
Male
Female Male
Male Female Male
Male Female
Female Male Female
Female
2
3 4
5
6
7
8
9
10
11 12
13 14 15
16 17
18 19 20
21
Gender
1
Patient Number
64
59 49 36
70 39
67 59 72
35 63
59
47
47
65
45
55
56 62
50
58
Age (Years)
TABLE 1 Patient Data
Yes
Yes Yes No
No No
Yes Yes Yes
No Yes
Yes
Yes
Yes
Yes
Yes
Yes
No Yes
No
Yes
Smoking Habits
Total
Total Partial Partial
Total Partial
Partial Total Partial
Partial Partial
Total
Partial
Partial
Partial
Partial
Partial
Partial Total
Partial
Partial
Edentulism
1 (25)
1 (26) 1 (16) 1 (16)
1 (15) 1 (26)
1 (17) 1 (26) 1 (26)
1 (16) 1 (16)
1 (27)
2 (16, 17)
2 (24, 26)
1 (26)
1 (16)
1 (17)
1 (25) 1 (14)
2 (25, 26)
1 (26)
Number of Implants (Sites)
Cylindrical
Cylindrical Cylindrical Conical
Cylindrical Conical
Cylindrical Cylindrical Cylindrical
Cylindrical Conical
Cylindrical
Cylindrical
Cylindrical
Conical
Cylindrical
Cylindrical
Cylindrical Cylindrical
Tramonti
Tramonti
Implant Type
Rough
Rough Rough Rough
Rough Rough
Machined Machined Rough
Rough Rough
Rough
Rough
Rough
Rough
Rough
Rough
Machined Rough
Machined
Machined
Implant Surface
1991
1993 1997 1998
1999
1999 2000
2002 2004 2004 2005 2005 2006 2006 2007 2007 2008 2009 2010
3.5 × 10; 3.5 × 10 3.75 × 13 5×9 3.75 × 11.5
3.75 × 11.5
4 × 10 5 × 10; 5 × 10 3.75 × 11; 6×9 5×9 3.75 × 13 4 × 12 4×9 4 × 10 4 × 11.5 3.75 × 11.5 4 × 10 3.75 × 10 4×9 5×7 4×9
2001
1990
Year of Implant Insertion
3.5 × 13
Implant Diameter and Length (mm)
11
5 7 13
36 2
205 48 3
3 2
4
2
3
6
34
1
8 7
8
39
Time from Placement to Diagnosis of Displacement (Months)
No
No No No
No Yes
No Yes No
No No
Yes
No
No
Yes
No
Yes
No Yes
No
No
Sinus Lift
4
0 3 3
9 4
3 3 4
12 4
5
2,0
8,5
2
4
5
6 4
2,4
12
Bone Height (mm)
No
No No No
No No
No No No
No No
Yes
No
Yes
Yes
Yes
Yes
No Yes
Yes
Yes
Sinusitis
None
None None None
None None
None None None
Pain in the sinus region None None
None
Nasal obstruction
None Nasal obstruction, headache Nasal obstruction, pain in the sinus region Pain in the sinus region, nasal discharge Nasal obstruction
Nasal obstruction, pain in the sinus region Pain in the sinus region, nasal discharge
Sinusitis Symptoms
Lateral wall approach
Lateral wall approach Lateral wall approach Lateral wall approach
Lateral wall approach Lateral wall approach
Lateral wall approach Lateral wall approach Lateral wall approach
Lateral wall approach Lateral wall approach
Lateral wall approach
Caldwell-Luc operation Caldwell-Luc operation Lateral wall approach
Caldwell-Luc operation
Lateral wall approach Caldwell-Luc operation Implant retrieval via alveolar ridge
Lateral wall approach
Caldwell-Luc operation
Surgical Treatment
Implant Displacement into Maxillary Sinus 3
4
Clinical Implant Dentistry and Related Research, Volume *, Number *, 2014
A
A
B
B
Figure 3 A, Patient 18 at implant insertion time. B, Patient 18 at displacement diagnosis.
Figure 2 A, Patient 9 at displacement diagnosis of implant in region 16. B, Patient 9 at displacement diagnosis of implant in region 17.
In four patients, the implant was displaced together with its cover screw (Figure 2), and in two cases the healing abutment was found to be displaced (Figure 3). In one case (patient 1), the implant actually fractured, and its apical part was displaced into the sinus (Figure 4). In three patients, two fixtures were found dislodged into the sinus (Figure 5). For patient 9, displacement occurred for two implants with two different installation times, with only some weeks in between (see Figure 2). The most frequently involved site was the upper first molar area (58.3%), followed by the second premolar and the second molar (16.6% each) and the first premolar (8.3%). The majority of the displaced implants were cylindrical (62.5%), followed by conical (16.6%) and Tramonti-type (8.3%). Only five implants (20.8%) had a
machined surface. Diameter and length distributions of the displaced implants are shown in Table 2. For six patients (six implant sites, 25%), a sinus lift procedure was performed at implant surgery time. Mean estimated bone height was 4.3 mm (range 0–12 mm); bone height was
ABSTRACT Background: One possible complication of implant surgery in the posterior maxilla is the displacement of implants into the maxillary sinus. Purpose: To report on clinical and radiological findings and on biological, surgical, and biomechanical considerations in cases of implant displacement. Materials and Methods: This is a retrospective study of 21 patients referred to the Department of Head and Neck Surgery, Second University of Naples, due to implants displaced into the maxillary sinus. Patient, implant, and treatment data were collected, and 1-year follow-up was made. Results: A total of 24 displaced implants were diagnosed and surgically removed through an antrostomy in the lateral sinus wall. Implant displacement occurred after functional loading in only one case; in the remaining cases, displacement occurred either perioperatively or postoperatively prior to loading. Besides the displacement, eight patients suffered from maxillary sinusitis, treated with a Caldwell-Luc operation. Healing was uneventful for all patients, and no sinusitis relapse or late postoperative complication was present at 1-year follow-up. Conclusions: It is reasonable to affirm that the major cause of displacement of implants is related, most of the time, to incorrect treatment planning and/or a poorly performed surgical procedure. When implant displacement occurs, the displaced foreign body has to be removed in order to avoid sinus pathology. KEY WORDS: dental implants, displacement, maxillary sinus, osseointegration, primary stability, sinus elevation
dental implants.3–15 There are also reports of oral implants displaced in the sphenoid16 and in the ethmoid sinus.17 Titanium dental implants have been used worldwide for over 40 years. The failure rate of endosseous implants is relatively low, but it is generally greater in the maxilla than in the mandible. Several anatomical features of the maxilla may prompt a higher rate of implant failure than that recorded in the mandible. The upper jaw often shows type IV alveolar bone (poor-quality, low-density cancellous bone and a very thin cortical layer). Besides, the dorsal segment of the maxilla presents some unique anatomic features and limitations. As is well known, tooth loss implies that the necessary stimulus to maintain bone trophism has disappeared, resulting in resorption of the alveolar process, which, in the posterior maxillary region, means a close relation between the sinus floor and the alveolar crest. Furthermore, pneumatization of the sinus through centrifugal
INTRODUCTION A foreign body in the maxillary sinus is a rare finding. Possible causes are injury or accident and dental treatments. The most commonly found foreign bodies are displaced fractured dental roots or, in some instances, whole teeth following tooth extraction procedures.1,2 Other foreign bodies include dental burs, endodontic material, impression materials, and, more recently,
Department of Oral and Maxillofacial Surgery, Second University of Naples, Naples, Italy Corresponding Author: Dr. Nicola Sgaramella, Department of Oral and Maxillofacial Surgery, Second University of Naples, Piazza Miraglia, 80100, Naples, Italy; e-mail: [email protected] © 2014 Wiley Periodicals, Inc. DOI 10.1111/cid.12244
1
2
Clinical Implant Dentistry and Related Research, Volume *, Number *, 2014
bone resorption, induced by the osteoclastic activity of the periosteum underlying the schneiderian membrane, usually occurs in the edentulous posterior region. These unique anatomical and physiological features, together with the progressive widening of implant treatment indications, make implant rehabilitation of the posterior maxilla a challenging issue; complications such as implant displacement into the maxillary sinus, apparently rare and sporadic, may well be underestimated. Indeed, the incidence of implant displacement into the maxillary sinus remains unknown because of the lack of cohort studies and the relatively few published case reports.3–15 The following paper is a retrospective study of 21 patients referred to the Department of Head and Neck Surgery, Second University of Naples, for implants displaced into the maxillary sinus. The surgical treatments performed shortly after the diagnosis of this complication, including treatment for possibly associated sinusitis and/or oroantral fistula, and the 1-year follow-up results are reported. MATERIALS AND METHODS In a 20-year period between 1990 and 2010, 21 patients (10 male, 11 female), aged 35–70 (mean 55 years), were referred to the Department of Head and Neck Surgery, Second University of Naples, due to clinical and radiological signs of implants displaced into the maxillary sinus (Figure 1). The displacement occurred during or after implant insertion in the posterior upper jaw. None of the patients underwent implant surgery in postextractive sites. Eight of these patients sought medical care because of sinusitis symptoms, one of the patients suffering also from the presence of an
oroantral fistula, while the remaining 13 patients were asymptomatic, so the detection of the displacement was done during other dental treatments or routine controls. The following patient data were collected: age; gender; smoking habits; type of edentulism; number of displaced implants; implant sites; implant type (conical, cylindrical or Tramonti); implant diameter and length; other displaced components; year of implant insertion; intervening time between implant insertion and detection of implant displacement; previous functional loading of the displaced implant; bone height at the implant site, which was estimated from conventional x-rays (panoramic and intraoral radiographs) taken at implant insertion time or at implant displacement diagnosis time and from the computed tomography (CT) or cone beam computed tomography (CBCT) examination performed prior to surgical treatment of the complication (the only exception being the case of patient 16, for whom a CBCT exam performed prior to implant surgery was available); sinus lift procedure simultaneous with implant placement; signs and/or symptoms of sinusitis; surgical treatment performed; and postoperative complications and/or relapse of sinus pathology at 1-year follow-up (Table 1). RESULTS A total of 24 displaced implants were diagnosed and surgically removed. Most of the implant displacements occurred during the second decade of the period covered by the present study. Among the patients with displaced implants, the majority were smokers (71.4%), and 15 out of 21 patients were partially dentate in the maxilla.
Figure 1 Patient 21, CT examination prior to the surgical removal of the displaced implant.
Male
Male
Female Female
Female
Male
Male
Female
Female
Male
Female Male
Male Female Male
Male Female
Female Male Female
Female
2
3 4
5
6
7
8
9
10
11 12
13 14 15
16 17
18 19 20
21
Gender
1
Patient Number
64
59 49 36
70 39
67 59 72
35 63
59
47
47
65
45
55
56 62
50
58
Age (Years)
TABLE 1 Patient Data
Yes
Yes Yes No
No No
Yes Yes Yes
No Yes
Yes
Yes
Yes
Yes
Yes
Yes
No Yes
No
Yes
Smoking Habits
Total
Total Partial Partial
Total Partial
Partial Total Partial
Partial Partial
Total
Partial
Partial
Partial
Partial
Partial
Partial Total
Partial
Partial
Edentulism
1 (25)
1 (26) 1 (16) 1 (16)
1 (15) 1 (26)
1 (17) 1 (26) 1 (26)
1 (16) 1 (16)
1 (27)
2 (16, 17)
2 (24, 26)
1 (26)
1 (16)
1 (17)
1 (25) 1 (14)
2 (25, 26)
1 (26)
Number of Implants (Sites)
Cylindrical
Cylindrical Cylindrical Conical
Cylindrical Conical
Cylindrical Cylindrical Cylindrical
Cylindrical Conical
Cylindrical
Cylindrical
Cylindrical
Conical
Cylindrical
Cylindrical
Cylindrical Cylindrical
Tramonti
Tramonti
Implant Type
Rough
Rough Rough Rough
Rough Rough
Machined Machined Rough
Rough Rough
Rough
Rough
Rough
Rough
Rough
Rough
Machined Rough
Machined
Machined
Implant Surface
1991
1993 1997 1998
1999
1999 2000
2002 2004 2004 2005 2005 2006 2006 2007 2007 2008 2009 2010
3.5 × 10; 3.5 × 10 3.75 × 13 5×9 3.75 × 11.5
3.75 × 11.5
4 × 10 5 × 10; 5 × 10 3.75 × 11; 6×9 5×9 3.75 × 13 4 × 12 4×9 4 × 10 4 × 11.5 3.75 × 11.5 4 × 10 3.75 × 10 4×9 5×7 4×9
2001
1990
Year of Implant Insertion
3.5 × 13
Implant Diameter and Length (mm)
11
5 7 13
36 2
205 48 3
3 2
4
2
3
6
34
1
8 7
8
39
Time from Placement to Diagnosis of Displacement (Months)
No
No No No
No Yes
No Yes No
No No
Yes
No
No
Yes
No
Yes
No Yes
No
No
Sinus Lift
4
0 3 3
9 4
3 3 4
12 4
5
2,0
8,5
2
4
5
6 4
2,4
12
Bone Height (mm)
No
No No No
No No
No No No
No No
Yes
No
Yes
Yes
Yes
Yes
No Yes
Yes
Yes
Sinusitis
None
None None None
None None
None None None
Pain in the sinus region None None
None
Nasal obstruction
None Nasal obstruction, headache Nasal obstruction, pain in the sinus region Pain in the sinus region, nasal discharge Nasal obstruction
Nasal obstruction, pain in the sinus region Pain in the sinus region, nasal discharge
Sinusitis Symptoms
Lateral wall approach
Lateral wall approach Lateral wall approach Lateral wall approach
Lateral wall approach Lateral wall approach
Lateral wall approach Lateral wall approach Lateral wall approach
Lateral wall approach Lateral wall approach
Lateral wall approach
Caldwell-Luc operation Caldwell-Luc operation Lateral wall approach
Caldwell-Luc operation
Lateral wall approach Caldwell-Luc operation Implant retrieval via alveolar ridge
Lateral wall approach
Caldwell-Luc operation
Surgical Treatment
Implant Displacement into Maxillary Sinus 3
4
Clinical Implant Dentistry and Related Research, Volume *, Number *, 2014
A
A
B
B
Figure 3 A, Patient 18 at implant insertion time. B, Patient 18 at displacement diagnosis.
Figure 2 A, Patient 9 at displacement diagnosis of implant in region 16. B, Patient 9 at displacement diagnosis of implant in region 17.
In four patients, the implant was displaced together with its cover screw (Figure 2), and in two cases the healing abutment was found to be displaced (Figure 3). In one case (patient 1), the implant actually fractured, and its apical part was displaced into the sinus (Figure 4). In three patients, two fixtures were found dislodged into the sinus (Figure 5). For patient 9, displacement occurred for two implants with two different installation times, with only some weeks in between (see Figure 2). The most frequently involved site was the upper first molar area (58.3%), followed by the second premolar and the second molar (16.6% each) and the first premolar (8.3%). The majority of the displaced implants were cylindrical (62.5%), followed by conical (16.6%) and Tramonti-type (8.3%). Only five implants (20.8%) had a
machined surface. Diameter and length distributions of the displaced implants are shown in Table 2. For six patients (six implant sites, 25%), a sinus lift procedure was performed at implant surgery time. Mean estimated bone height was 4.3 mm (range 0–12 mm); bone height was
